Problem: $8ab - 5ac + 9a + 5 = -2b - 6$ Solve for $a$.
Solution: Combine constant terms on the right. $8ab - 5ac + 9a + {5} = -2b - {6}$ $8ab - 5ac + 9a = -2b - {11}$ Notice that all the terms on the left-hand side of the equation have $a$ in them. $8{a}b - 5{a}c + 9{a} = -2b - 11$ Factor out the $a$ ${a} \cdot \left( 8b - 5c + 9 \right) = -2b - 11$ Isolate the $a$ $a \cdot \left( {8b - 5c + 9} \right) = -2b - 11$ $a = \dfrac{ -2b - 11 }{ {8b - 5c + 9} }$ We can simplify this by multiplying the top and bottom by $-1$. $a= \dfrac{2b + 11}{-8b + 5c - 9}$